diff --git a/debuginfo-tests/CMakeLists.txt b/debuginfo-tests/CMakeLists.txt
--- a/debuginfo-tests/CMakeLists.txt
+++ b/debuginfo-tests/CMakeLists.txt
@@ -13,6 +13,11 @@
   not
   )
 
+# The Windows builder scripts pass -fuse-ld=lld.
+if (WIN32)
+  set(DEBUGINFO_TEST_DEPS ${DEBUGINFO_TEST_DEPS} lld)
+endif()
+
 # If we don't already have Python 3, throw away any previous results and try to
 # find it again.
 set(DEBUGINFO_UNSET_PYTHON3 OFF)
diff --git a/debuginfo-tests/dexter/dex/builder/Builder.py b/debuginfo-tests/dexter/dex/builder/Builder.py
--- a/debuginfo-tests/dexter/dex/builder/Builder.py
+++ b/debuginfo-tests/dexter/dex/builder/Builder.py
@@ -80,12 +80,14 @@
                 stderr=subprocess.PIPE)
             out, err = process.communicate()
             returncode = process.returncode
+        out = out.decode('utf-8')
+        err = err.decode('utf-8')
         if returncode != 0:
             raise BuildScriptException(
                 '{}: failed with returncode {}.\nstdout:\n{}\n\nstderr:\n{}\n'.
                 format(script_path, returncode, out, err),
                 script_error=err)
-        return out.decode('utf-8'), err.decode('utf-8'), builderIR
+        return out, err, builderIR
     except OSError as e:
         raise BuildScriptException('{}: {}'.format(e.strerror, script_path))
 
diff --git a/debuginfo-tests/dexter/dex/builder/scripts/windows/clang.bat b/debuginfo-tests/dexter/dex/builder/scripts/windows/clang.bat
--- a/debuginfo-tests/dexter/dex/builder/scripts/windows/clang.bat
+++ b/debuginfo-tests/dexter/dex/builder/scripts/windows/clang.bat
@@ -1,4 +1,4 @@
-setlocal EnableDelayedExpansion
+@setlocal EnableDelayedExpansion
 
 for %%I in (%SOURCE_INDEXES%) do (
   %PATHTOCLANGPP% -fuse-ld=lld -c !COMPILER_OPTIONS_%%I! !SOURCE_FILE_%%I! -o !OBJECT_FILE_%%I!